7mm Weatherby Mag and powders???

Just can't seem to get anything to group under 2 1/2 inches at 100 yards using IMR 4831. Loaded through the whole spectrum from 68 gr to 71.5. I was putting the 150 gr Barnes TSX at the recommended OAL and it is through a Weatherby Mark V. Is it possible that this is just the best that this powder will do with the 150 grainers. In the book it calls for H4350 to be the most accurate powder. I guess I will just get a pound of that to see if it will work. Has anybody else got IMR 4831 to group with this bullet???? Or is it just me and my gun?

If you enjoyed reading about "7mm Weatherby Mag and powders???" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!

Funshooter45

July 13, 2011, 07:37 PM

I have a couple of 7 mm mags that I load for They are both very sensitive to the bullet I use. The most recent one finally showed the bullet it liked the best was a 160 gr Sierra BTSP. When I tried that bullet, it magically started giving me nice groups with both W780 and IMR - 7828 powders. I suspect it will like 4831 just fine when I try that too. For some reason the 160 gr Sierras gave much better groups in that rifle than the 162 gr Hornadys. My other 7 mm prefers 140 gr bullets no matter who makes them. the 4831 powder works fine in it as long as I'm giving it good bullets in its preferred weight range.

jonn5335

July 14, 2011, 07:18 PM

My 7mm like 162 grn Hornadys with H4831 try dirrerent bullets

snuffy

July 14, 2011, 09:07 PM

7mm Weatherby Mag and powders???

Whatever loads my 7mm rem mag may or may not like has absolutely no bearing on what a wheatherby 7mm mag would like. It's an entirely different cartridge.

GooseGestapo

July 15, 2011, 02:42 AM

Most likely, it's the bullet that the rifle doesn't care for. The long free-bore of the 7mmWby likely is having some issues with the all-copper bullet.

I'd try a different bullet.

But, I've also had better results from my .300RUM and .257Wby with RL25 powder. Secondarily, I'd try RL22 and IMR7828 from the 7mmWby.

In reality, there is very little difference between the 7mmWby and the 7mmRemMag. Differences are mostly the rifles they are chambered in, with the 7mmWby typically having a 26" bbl. vs. 24" for the 7mmRemMag. Also, the typically short throat of the 7mmRem makes it a bit of a different animal.... The powder choices are identical though.

If you enjoyed reading about "7mm Weatherby Mag and powders???" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!